Tens of thousands of prostate cancer (CaP) patients undergo radical prostatectomies (RP) in the United States each year. Despite the effectiveness of RP in treating CaP, 15% to 40% of men will experience, following RP, disease progression manifested as biochemical recurrence, local or distant cancer recurrence, or cancer death. The Gleason sum (GS) is a measure used by pathologists to assess tissue morphology. In Gleason scoring, the two most common Gleason patterns are scored on a scale of 1 to 5. The sum of the two scores is the Gleason Sum, which ranges from 2 through 10 and is the conventional method of predicting CaP progression. High GS cases are correlated with cancer progression. Patients with high GS may be provided with more aggressive secondary treatments in addition to RP. GS is, however, only associated with cancerous foci. Conventional methods of cancer grading that use only GS are unable to grade patterns in benign stromal areas proximal to cancer foci.
Pathologists have conventionally used microscopes to conduct visual evaluation of histological tissue. Manual evaluation of histological tissue is excessively time consuming in a clinical environment, and may suffer from poor inter-interpreter agreement. Digital whole slide scanners have enabled automated evaluation of histological tissue through quantitative histomorphometry (QH). Conventional QH methods have used nuclear shape as a predictor of CaP. Other conventional QH methods have used nuclear roundness variance to evaluate the tumor area of prostate tissue for CaP progression with greater effectiveness than traditional Gleason scoring.
Some conventional methods have demonstrated the field effect through higher nuclear morphometric scores associated with benign prostate nuclei found near tumor regions. However, conventional methods that investigate benign prostate nuclei use Feulgen-staining of DNA, which is not a standard staining technique employed by pathologists investigating CaP. Thus, conventional methods for predicting CaP progression that rely on just GS use only the tumor tissue to gather information about morphological features. Conventional methods that attempt to gather information from benign regions use non-standard staining techniques that pathologists may not be trained to analyze. The use of non-standard staining techniques may increase the time required to implement those methods, and reduce the accuracy of those methods.